Although thinking about it - my question is probably more physics but non the less I would like to know.

When i'm in the shower it seems that water seems to defy gravity and creep down the bottom of my arm to huge angles where gushes of water is sent to a completely different direction it would otherwise do.

But it does seem to be only my arms, i'm not sure if it is anything special about arms themselves or its just the position of how standing up in the shower makes.

What you're describing is a property of water called cohesion. Water molecules are polar, which means that there is a separation of charges on two sides of the molecule. This makes the water molecules line up and want to stick together. Even tho these effects take place on the molecular scale, they add up and have effects on larger volumes of water, making the water flow as a cohesive stream.

The direction of the flow depends on a variety of factors including gravity, and the position and shape of your arms. The motion of fluids is described by a set of equations called the navier-stokes equations.